This application claims the benefit under 35 U.S.C. §119(a) of Korean Patent Application No. 2003-18770, filed on Mar. 26, 2003, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
1. Field of the Invention
The present invention relates to an ink-jet printer. More particularly, the present invention relates to an ink-jet printer having a head gap adjusting apparatus which adjusts a distance between a printing medium and a nozzle according to the thickness of the printing medium.
2. Description of the Related Art
In general, ink-jet printers print an image by ejecting ink onto a printing medium. Specifically, ink-jet printers print a desired image on the printing medium by ejecting ink through nozzles of an ink cartridge which stores ink, while moving a carriage which holds the ink cartridge side to side. The ink cartridge typically includes a printhead that provides a plurality of nozzles through which ink is ejected downwardly.
A space (hereinafter, referred to as a head gap) between the printhead and the printing medium should be maintained at a constant level, so as to optimize printing quality. In other words, the smaller the head gap is, the larger the printed pixels are, and the larger the head gap is, the smaller the printed pixels are. As such, when the head gap is too large the shape of each pixel is deformed, and the quality of a recorded image is lowered.
Printing quality can also be deteriorated if the head gap is too small. In particular, if the head gap is not maintained in an optimum state, undried ink on the printing medium can be transferred back to the printhead. When the carriage in which the printhead is received moves in a reciprocating motion perpendicular to a printing medium ejecting direction, the printhead can contact undried ejected ink and smear the ink on the printing medium.
An apparatus for adjusting a head gap according to the thickness of a printing medium to be used therein is disclosed in U.S. Pat. No. 5,751,301.
In the above-disclosed apparatus for adjusting the head gap, a carriage is rotated on a guide shaft such that a space between a printhead and the printing medium is adjusted according to the thickness of the printing medium. However, in the above described apparatus for adjusting the head gap, a user is required to adjust the head gap manually. Thus, there are operational inconveniences, and the head gap cannot be precisely adjusted.